<figure id="attachment_479899" class="wp-caption alignnone" style="width: 1512px;" aria-describedby="caption-attachment-479899"><a href="#" data-ident_hash="904c9800"><img src="https://res.cloudinary.com/fridaydigital/image/private/t_article_image/wpmedia/2026/09/65bb35eb053fcad3059e13ccd601fc07.jpg" alt=""></a><figcaption id="caption-attachment-479899" class="wp-caption-text">As you stroll through nature, record into your smartphone’s voice memo app one after another whatever catches your eye or comes to mind. Since you don’t have to share it with anyone, freely weave a story that makes you feel more energized.</figcaption></figure>
In recent years, it has been pointed out that loneliness, like obesity and smoking, may increase the risk of death and dementia. At the same time, we live in an age of smartphones, allowing us to stay connected with someone at any time through social media. Many people may think, “I have nothing to do with loneliness” or “I’m healthy both mentally and physically because I have connections with other people.”
But that sense of security has a hidden pitfall. Neurosurgeon Michihito Sugawara warns, “If you use your smartphone incorrectly, there is a risk that you may continue to damage your brain without even realizing it.” Smartphones are not just for connecting with others through social media. Here, we introduce ways to use your smartphone in ways that are good for your brain and that you can put into practice immediately in your daily life.
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<h2>Three factors that cause smartphone brain fatigue</h2>
— I imagine communicating with others through social media on smartphones can help alleviate loneliness among seniors, especially seniors who live alone…
“People in the Reiwa era are more familiar with digital technology than ever before, but they are experiencing not only its benefits but also its drawbacks. In particular, among seniors, whose ‘healthy life expectancy’ should ideally be increasing, more and more people are complaining of problems such as ‘I don’t feel motivated,’ ‘I can’t remember people’s names,’ and ‘My head always feels heavy.’
Some of that forgetfulness and fatigue may not be solely due to ‘aging,’ but could potentially be caused by ‘how we use our smartphones.’” (All quotation marks below are Sugawara’s words.)
— Indeed, we often hear the term “smartphone brain fatigue” these days.
“Strictly speaking, ‘smartphone brain fatigue’ is not a medical term. However, it accurately describes a condition that many people today experience. In the past, fatigue was caused by moving the body itself. Getting from place to place and working were primarily physical activities.
Today, desk work has become the norm, and it could be said that physical fatigue has decreased. However, in its place, the brain has begun working excessively and continuously due to constant access to digital technology, and this has become the norm.”
— Why does smartphone brain fatigue occur?
“There are three main factors behind brain fatigue caused by smartphones. First is simply stimulation from light. The strong light emitted by smartphone screens, particularly blue light, suppresses the secretion of melatonin, a hormone that affects the body’s internal clock.
As a result, sleep quality deteriorates, leading to brain fatigue. When melatonin levels are low, the function of the glymphatic system, which removes waste products from the brain during sleep, is inhibited.
Another problem is prolonged dopamine-induced excitement. The striatum, the center of the brain’s reward system, releases dopamine, a pleasure-related chemical, whenever we encounter new information on social media. This dopamine creates a desire in us to see more.
To satisfy that desire, social media keeps feeding us new information. With an endless flood of information coming in, the brain becomes completely trapped in a loop of seeking and reward. As a result, the functioning of the prefrontal cortex, which is responsible for concentration and decision-making, becomes sluggish, reducing our ability to think deeply.”
The third factor is said to be emotional fluctuations.
“On social media, other people’s successes and happiness are presented to us. Of course, there are days when we can happily celebrate them. But depending on our mental state, there are also days when we may unknowingly feel jealousy or inferiority. Social media also contains plenty of information that stirs up anger and anxiety, which can cause stress to accumulate.
These daily emotional fluctuations gradually affect the autonomic nervous system and disrupt its balance. These three factors can ultimately lead to smartphone brain fatigue, causing symptoms such as being unable to sleep, feeling irritable, feeling mentally foggy, being unable to concentrate, and becoming forgetful.”
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<div data-friday-nextpage-lead="The brain is in a state of excitement caused by dopamine"></div>
<figure id="attachment_479900" class="wp-caption alignnone" style="width: 1440px;" aria-describedby="caption-attachment-479900"><a href="#" data-ident_hash="23b138c8"><img src="https://res.cloudinary.com/fridaydigital/image/private/t_article_image/wpmedia/2026/09/aba7edd8a72da4556b3b4f8d34773211.jpg" alt=""></a><figcaption id="caption-attachment-479900" class="wp-caption-text">Doctor Sugawara recommends that, rather than immediately searching for a word you cannot remember, you spend even just 10 seconds searching through the drawers of your memory.</figcaption></figure>
<h2>Use your smartphone with an output-oriented brain!!</h2>
— So even when we think we’re simply looking at our smartphones, the brain remains in a state of dopamine-induced excitement. I’ve certainly opened social media for no particular reason and then realized that hours had passed. And I felt strangely tired afterward.
“The mechanism behind the brain’s release of dopamine is a remnant of a time in human evolution when obtaining new information was advantageous for survival. Before humans had civilization, they increased their chances of survival by responding quickly to unknown events.
However, in modern times, this mechanism can become overactive. The constant stream of news and social media information keeps stimulating the brain, making it prone to falling into a chronic state of scattered attention.”
— Do we need to take the drastic step of quitting smartphones altogether?
“No, I don’t recommend such drastic measures. It is necessary to reconsider how you engage with social media, but I don’t think you need to distance yourself from smartphones themselves. In fact, there have been reports that some people experience increased anxiety and feelings of loneliness when they are forced to give up their smartphones, resulting in elevated levels of cortisol, a stress hormone.
In modern society, smartphones have already become part of the foundation of our daily lives. Simply cutting them out could place an unnecessary burden on both the mind and body.”
— Is there a way to use smartphones without tiring out the brain?
“Of course. The effects smartphones have on the human brain and mind can be either poison or medicine, depending on how they are used. So far, I have explained the poisonous side, but now I’d like to introduce ways to use smartphones as medicine. The important thing is to shift from an input-oriented brain to an output-oriented brain.”
— What specific methods can we use to turn the brain toward output?
“I recommend taking a walk while recording yourself talking. Every day, all of us encounter countless flashes of inspiration, emotional fluctuations, and even fragments of memories. But most of them have already slipped away by the moment we notice them and never return in exactly the same form.
Record those irreplaceable moments using your smartphone’s voice memo function (the ‘Voice Memos’ app on iPhone or the ‘Recorder’ app on Android). Talking to yourself through voice memos is more than simply keeping a record. For the brain, it is a highly multifaceted form of training. First, the act of speaking itself moves the muscles of the mouth and throat, stimulating the motor cortex. Then, listening to your own voice in real time activates the auditory cortex.
Furthermore, as you try to maintain the flow of what you are saying, your working memory—a function of the brain that acts like a notepad and workbench for simultaneously retaining and manipulating information—goes into full gear, connecting the context from one part of your speech to another. It is an extremely efficient form of brain exercise that simultaneously engages multiple areas, including language, emotion, and autobiographical memory.”
— There are often scenes in dramas where a famous detective or doctor talks through their thoughts aloud and suddenly realizes the truth.
“The experience of hearing your own voice with your own ears provides strong stimulation to the brain. It enables you to engage in deeper processing than simply thinking inside your head.
For seniors in particular, taking a walk while recording yourself talking can be very meaningful. More people are living alone, which means there are fewer opportunities to use their voices. With voice memos, you are not talking to someone else; you are using your own voice and receiving it through your own ears, so you can do it regardless of the time or place.
Moving the mouth and throat is also considered important as part of rehabilitation. Patients with Parkinson’s disease are sometimes encouraged to talk a lot or go to karaoke. That shows just how important speaking is to both the brain and the body.”
— I imagine there are people who have trouble coming up with things to say. What kinds of things should they record while walking?
“Anything is fine (laughs). You can simply narrate what you see and hear during your walk and how it makes you feel. If you see a dog out for a walk and think, ‘How cute,’ just put that feeling into words however you like. If you notice a change in the season, say out loud, ‘It feels like the end of summer is in the air,’ or ‘An autumn-like breeze has started to blow.’
Don’t think, ‘I have to speak well’ or ‘I have to say something interesting.’ Your smartphone has plenty of storage. Remove filters such as ‘This is embarrassing’ or ‘This is boring,’ and directly put the emotions and thoughts that come to mind into words and record them.”
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<div data-friday-nextpage-lead="“Autobiographical Memory” in the Brain"></div>
<h2>Reduce your input and you&#8217;ll begin to see you own life</h2>
— You mentioned that, in addition to language and emotion, autobiographical memory is also activated.
“For example, while taking a walk, you might remember, ‘There used to be a ramen shop here.’ By talking aloud about the taste of the ramen you ate there, what the inside of the restaurant was like, and who you visited with, you activate your brain’s autobiographical memory. So it’s not simply reminiscing; it also serves as training to strengthen your ability to recall memories.”
— Are there any points to keep in mind when making taking a walk while recording yourself talking a habit?
“Since you’re walking, I don’t recommend taking notes with a pen or typing on your smartphone for safety reasons. It’s also important to have the mindset that continuing the habit is not the goal.
The moment you think of brain training with a smartphone as a daily task that I have to do, it stops being enjoyable and becomes an obligation. The habit you worked to establish can turn into a source of stress, and the smartphone can once again become poison. It’s important to continue only within a range that doesn’t place undue pressure on you.”
— Finally, do you have a message for our readers?
“Let’s reduce the excessive input of endlessly watching videos and scrolling through social media. Even if the information concerns a hobby you love or an entertainer you passionately support, continually taking in more and more of it can only be harmful to the brain. In that state, the brain has no time to rest, and eventually it will exceed its processing capacity and become overloaded.
The brain is more likely to perform at its best when it isn’t overloaded with information. Reduce your input and turn your attention inward. Step away from the flood of information, and during moments when you simply let your mind wander, fundamental questions such as ‘What do I truly want to value?’ will begin to emerge. Using your brain at full capacity for the things that matter to you should have a major impact on the quality of your life from here on.”
— Thank you very much. I think I’ll walk back to the station while recording my thoughts about this interview on my smartphone.
<figure id="attachment_479902" class="wp-caption alignnone" style="width: 240px;" aria-describedby="caption-attachment-479902"><a href="#" data-ident_hash="50142b86"><img src="https://res.cloudinary.com/fridaydigital/image/private/t_article_image/wpmedia/2026/09/5815908cb739a77fcc2af0b299b037c2-1-rotated.jpg" alt=""></a><figcaption id="caption-attachment-479902" class="wp-caption-text">In Dr. Sugawara’s latest book, &#8220;A Smartphone That Serves as Medicine: Good Habits for Your Brain After 50, Taught by a Neurosurgeon&#8221; (Kawade Shobo Shinsha), he introduces various other habits for stimulating the brain in addition to the talking-to-yourself walk featured in this article.</figcaption></figure>
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Reporting and writing: Yutaka Sano Yutaka Sano is a freelance writer whose main areas of coverage are business and the humanities. He is active across various media, including magazines and online publications, primarily conducting interviews and writing articles. He has authored numerous books.
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Michihito Sugawara
Neurosurgeon. After graduating from Kyorin University School of Medicine, he worked at the National Center for Global Health and Medicine, specializing in emergency neurological conditions such as subarachnoid hemorrhage and cerebral infarction. In 2015, he opened the Sugawara Neurosurgery Clinic. He established a medical approach centered on treatment based on one’s goals in life, providing care that supports patients not only medically but also in terms of their emotional well-being and way of life.
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 Yutaka Sano, courtesy of Mr. Sugawara (profile photo)

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